Assisted catheter advancement

ABSTRACT

A catheter assembly may include an introducer needle coupled to a needle hub, an intermediate member having a contact surface, a resilient member, and a ramp member. The resilient member may be coupled to one of the needle hub and the intermediate member. The ramp member may be coupled to the other one of the needle hub and the intermediate member. The resilient member may engage a ramp surface of the ramp member and impart a force on the intermediate member in a distal direction. The contact surface of the intermediate member may engage a proximal surface of a catheter adapter body and urge the catheter adapter body in the distal direction such that a catheter projecting from the catheter adapter body may be translated in the distal direction relative to the introducer needle.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/081,911, filed Oct. 27, 2020, and entitled ASSITED CATHETERADVANCEMENT, which claims the benefit of U.S. Provisional PatentApplication No. 62/934,370, filed Nov. 12, 2019, and entitled ASSISTEDCATHETER ADVANCEMENT, which are incorporated herein in their entirety.

BACKGROUND

Catheters are commonly used for a variety of infusion therapies. Forexample, catheters may be used for infusing fluids into a patient suchas saline solution, medication, total parenteral nutrition, etc.Catheters may also be used for withdrawing blood from the patient.

A common type of catheter is an over-the-needle peripheral intravenouscatheter (“PIVC”). Other common types of catheters include, but are notlimited to, peripherally inserted central catheters (“PICC”), centralvenous catheters (“CVC”), etc.

As its name implies, the over-the-needle PIVC may be mounted over anintroducer needle having a sharp distal tip. The PIVC and the introducerneedle may be assembled so that the distal tip of the introducer needleextends beyond the distal tip of the PIVC with the bevel of the needlefacing away from skin of the patient. The PIVC and the introducer needleare typically inserted at a shallow angle through the skin and into ablood vessel of the patient, such as an artery, a vein, or any othervasculature of the patient. Once the PIVC has been properly placedwithin the blood vessel, the introducer needle may be withdrawn and thePIVC may be secured within the blood vessel by securing a catheteradapter (coupled with the PIVC) to the skin of the patient withdressing.

Some PIVC's can be associated with various additional components, suchas valving components, needle safety components, etc., which may providemany additional useful features to clinicians. However, these additionalcomponents may also introduce undesirable characteristics to a PIVCsystem. For example, these additional components may lead to: (1) anincreased overall length of a PIVC system, requiring a longer introducerneedle; (2) new sources of friction transmitted to the introducer needlevia the additional/longer components (e.g., the introducer needle mayexperience higher early stage drag forces as the introducer needle iswithdrawn/advanced through the additional/longer components. This mayinterfere with a clinician's tactile sensation and ability to properlyplace and maintain a catheter within a patient's vein); and (3) anincreased length of the introducer needle that is unsupported by othercomponents of the PIVC system as the introducer needle is withdrawn fromthe other components of the PIVC system. This longer “unsupportedportion” of the introducer needle may result in increased flexion thatcan allow other parts of the PIVC system to “wobble” back and forth in aflimsy manner and may result in dislodgment of the catheter from thevein. Accordingly, improved catheter assemblies, systems, and methodswould be desirable.

The subject matter claimed herein is not limited to embodiments thatsolve any disadvantages or that operate only in environments such asthose described above. Rather, this background is only provided toillustrate one example technology area where some implementationsdescribed herein may be practiced.

SUMMARY

The present disclosure generally relates to catheter assemblies,systems, and methods. The various catheter assemblies, systems, andmethods of the present disclosure have been developed in response to thepresent state of the art, and in particular, in response to the problemsand needs in the art that have not yet been fully solved by currentlyavailable catheter assemblies, systems, and methods for inserting acatheter into a blood vessel of a patient.

In some embodiments, a catheter system may include a needle assembly, adriving spring, and a needle-safety shield. The needle assembly mayinclude an introducer needle and a needle hub coupled to the introducerneedle. The driving spring may be coupled to the needle hub. The drivingspring may include a superior portion having a first spring arm, asecond spring arm, and a first cross-member coupling the first springarm to the second spring arm. The driving spring may also include aninferior portion having a third spring arm, a fourth spring arm, and asecond cross-member coupling the third spring arm to the fourth springarm. The driving spring may further include a first resilient portionand a second resilient portion. The first resilient portion may couplethe first spring arm to the third spring arm and the second resilientportion may couple the second spring arm to the fourth spring arm. Thefirst and second resilient portions may also apply a bias force to thefirst and second cross-members to urge the first and secondcross-members toward each other. The needle-safety shield may include acontact surface disposed at a distal end of the needle-safety shield,and the needle-safety shield may be configured to slidably receive theintroducer needle therein. The needle-safety shield may also include aramp member disposed at a proximal end of the needle-safety shield. Theramp member may include a first ramp surface configured to receive afirst guide surface of the first cross-member, a second ramp surfaceconfigured to receive a second guide surface of the first cross-member,a third ramp surface configured to receive a third guide surface of thesecond cross-member, and a fourth ramp surface configured to receive afourth guide surface of the second cross-member. The driving spring maybe configured to engage the ramp member and impart a force on theneedle-safety shield to urge the needle-safety shield in a distaldirection relative to the needle hub. The contact surface of theneedle-safety shield may engage a proximal surface of a catheter adapterbody and urge the catheter adapter body in the distal direction relativeto the needle hub and a catheter projecting from a distal end of thecatheter adapter body may be translated in the distal direction relativeto the introducer needle.

In some embodiments of the catheter system, the first and secondcross-members may be configured to grasp the introducer needle betweenthe first and second cross-members as the first and second cross-membersare urged together.

In some embodiments of the catheter system, the first ramp surface mayinclude a first concave surface portion, the second ramp surface mayinclude a second concave surface portion, the third ramp surface mayinclude a third concave surface portion, and the fourth ramp surface mayinclude a fourth concave surface portion.

In some embodiments of the catheter system, the first concave surfaceportion may include a first radius, the second concave surface portionmay include a second radius, the third concave surface portion mayinclude a third radius, and the fourth ramp surface may include a fourthradius.

In some embodiments of the catheter system, the first radius, the secondradius, the third radius, and the fourth radius may be substantiallyequal to each other.

In some embodiments of the catheter system, the ramp member may includeat least one plateau portion.

In some embodiments of the catheter system, the ramp member may includeat least one stop bump adjacent to the at least one plateau portion.

In some embodiments, a catheter assembly may include an introducerneedle coupled to a needle hub, an intermediate member, a resilientmember, and a ramp member. The intermediate member may include a contactsurface disposed at a distal end of the intermediate member. Theintermediate member may be configured to slidably receive the introducerneedle therethrough. The resilient member may be coupled to one of theneedle hub and the intermediate member. The ramp member may be coupledto the other one of the needle hub and the intermediate member. Theresilient member may be configured to engage at least one ramp surfaceof the ramp member and impart a force on the intermediate member to urgethe intermediate member in a distal direction relative to the needlehub. The contact surface of the intermediate member may engage aproximal surface of a catheter adapter body and urge the catheteradapter body in the distal direction relative to the needle hub and acatheter projecting from a distal end of the catheter adapter body maybe translated in the distal direction relative to the introducer needle.

In some embodiments of the catheter assembly, the resilient member mayinclude a driving spring. The driving spring may include a superiorportion having a first spring arm, a second spring arm, and a firstcross-member coupling the first spring arm to the second spring arm. Thedriving spring may also include an inferior portion having a thirdspring arm, a fourth spring arm, and a second cross-member coupling thethird spring arm to the fourth spring arm. The driving spring may alsoinclude a first resilient portion and a second resilient portion. Thefirst resilient portion may couple the first spring arm to the thirdspring arm, the second resilient portion may couple the second springarm to the fourth spring arm, and the first and second resilientportions may apply a bias force to the first and second cross-members tourge the first and second cross-members toward each other. In someembodiments, the catheter system may include more than two resilientportions and/or more than four ramp surfaces.

In some embodiments of the catheter assembly, the first and secondcross-members may be configured to grasp the introducer needle betweenthe first and second cross-members as the first and second cross-membersare urged together.

In some embodiments of the catheter assembly, the at least one rampsurface of the ramp member may include a first ramp surface configuredto receive a first guide surface of the first cross-member, a secondramp surface configured to receive a second guide surface of the firstcross-member, a third ramp surface configured to receive a third guidesurface of the second cross-member, and a fourth ramp surface configuredto receive a fourth guide surface of the second cross-member.

In some embodiments of the catheter assembly, the at least one rampsurface may include a concave surface portion having a first radius.

In some embodiments of the catheter assembly, the at least one rampsurface may include a plateau portion.

In some embodiments of the catheter assembly, the at least one rampsurface may include a stop bump intermediate the concave surface portionand the plateau portion.

In some embodiments, a method of inserting a catheter into a bloodvessel of a patient may be facilitated through use of a catheterassembly that may include an introducer needle coupled to a needle hub,an intermediate member having a contact surface disposed at a distal endof the intermediate member, a resilient member coupled to one of theneedle hub and the intermediate member, and a ramp member coupled to theother one of the needle hub and the intermediate member. The method mayinclude inserting a distal end of the introducer needle within a bloodvessel of the patient, and advancing the intermediate member proximallyrelative to the introducer needle, thereby: (1) engaging the resilientmember with a ramp surface of the ramp member to impart a force on theintermediate member and urge the intermediate member in a distaldirection relative to the needle hub; (2) engaging the contact surfaceof the intermediate member with a proximal surface of a catheter adapterbody to urge the catheter adapter body in the distal direction relativeto the needle hub; and (3) urging the catheter coupled to the catheteradapter body in the distal direction relative to the introducer needleuntil a distal end of the catheter is inserted within the blood vessel.

In some embodiments of the method, the method may further include movingthe needle hub and the introducer needle in a proximal directionrelative to the catheter, and withdrawing the introducer needle from thecatheter.

In some embodiments of the method, the resilient member may include adriving spring. The driving spring may include a superior portion havinga first spring arm, a second spring arm, and a first cross-membercoupling the first spring arm to the second spring arm. The drivingspring may also include an inferior portion having a third spring arm, afourth spring arm, and a second cross-member coupling the third springarm to the fourth spring arm. The driving spring may further include afirst resilient portion and a second resilient portion. The firstresilient portion may couple the first spring arm to the third springarm, the second resilient portion may couple the second spring arm tothe fourth spring arm, and the first and second resilient portions mayapply a bias force to the first and second cross-members to urge thefirst and second cross-members toward each other.

In some embodiments of the method, the first and second cross-membersmay be configured to grasp the introducer needle between the first andsecond cross-members as the first and second cross-members are urgedtoward each other. The method may further include grasping theintroducer needle between the first and second cross-members of thedriving spring as the introducer needle is at least partially withdrawnfrom the catheter.

In some embodiments of the method, the ramp surface may include a firstramp surface configured to receive a first guide surface of the firstcross-member, a second ramp surface configured to receive a second guidesurface of the first cross-member, a third ramp surface configured toreceive a third guide surface of the second cross-member, and a fourthramp surface configured to receive a fourth guide surface of the secondcross-member. The method may further include: (1) engaging the firstguide surface with the first ramp surface and imparting a first forcethat urges the intermediate member in the distal direction relative tothe needle hub; (2) engaging the second guide surface with the secondramp surface and imparting a second force that urges the intermediatemember in the distal direction relative to the needle hub; (3) engagingthe third guide surface with the third ramp surface and imparting athird force that urges the intermediate member in the distal directionrelative to the needle hub; and (4) engaging the fourth guide surfacewith the fourth ramp surface and imparting a fourth force that urges theintermediate member in the distal direction relative to the needle hub.

In some embodiments of the method, the ramp surface may include aconcave surface portion having a first radius. The method may furtherinclude engaging the resilient member with the concave surface portionto impart the force on the intermediate member and urge the intermediatemember in the distal direction relative to the needle hub.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the embodiments of the present disclosure, asclaimed. It should be understood that the various embodiments of thepresent disclosure are not limited to the arrangements andinstrumentality shown in the drawings. It should also be understood thatthe embodiments of the present disclosure may be combined, or that otherembodiments may be utilized and that structural changes, unless soclaimed, may be made without departing from the spirit or scope of thevarious embodiments of the present disclosure. The following detaileddescription is, therefore, not to be taken in a limiting sense.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be described and explained with additionalspecificity and detail through the use of the accompanying drawings inwhich:

FIG. 1A is an exploded view of an example catheter system, according tosome embodiments;

FIG. 1B is a cross-sectional side view of the example catheter system ofFIG. 1A, after assembly;

FIG. 2A is a perspective top view of a needle-safety shield, accordingto some embodiments;

FIG. 2B is a perspective bottom view of the needle-safety shield of FIG.2A;

FIG. 2C is a side view of the needle-safety shield of FIG. 2A;

FIG. 3A is a perspective top view of a driving spring, according to someembodiments;

FIG. 3B is a front view of the driving spring of FIG. 3A;

FIG. 3C is a perspective top view of the driving spring of FIG. 3A,showing the distal ends of the driving spring pulled apart;

FIGS. 4A-4C illustrate various side views of the driving spring of FIG.3A as it is loaded onto a ramp member of the needle-safety shield ofFIG. 2A; FIG. 4A is a side view of the driving spring before it isloaded onto the ramp member; FIG. 4B is a side view of the drivingspring sliding up the ramp member; and FIG. 4C is a side view of thedriving spring when it is fully loaded onto the ramp member;

FIG. 5A is a perspective top view of a driving spring being loaded ontoa ramp member, according to some alternative embodiments;

FIG. 5B is a cross-sectional side view of the driving spring fullyloaded onto the ramp member of FIG. 5A;

FIG. 6 is a cross-sectional side view of an example catheter systemincorporating the driving spring and ramp member of FIG. 5A.

FIG. 7 is a partial cross-sectional side view of an example cathetersystem, according to some alternative embodiments; and

FIG. 8 is a flow chart of a method for inserting a catheter into a bloodvessel of a patient.

It is to be understood that the Figures are for purposes of illustratingthe concepts of the present disclosure and may not be drawn to scale.Furthermore, the Figures illustrate exemplary embodiments and do notrepresent limitations to the scope of the present disclosure.

DESCRIPTION OF EMBODIMENTS

Exemplary embodiments of the present disclosure will be best understoodby reference to the Figures, wherein like parts are designated by likenumerals throughout. It will be readily understood that the componentsof the present disclosure, as generally described and illustrated in theFigures herein, could be arranged and designed in a wide variety ofdifferent configurations. Thus, the following more detailed descriptionof the embodiments of the apparatus and systems, as represented in theFigures, is not intended to limit the scope of the present disclosure,as claimed in this or any other application claiming priority to thisapplication, but is merely representative of exemplary embodiments ofthe present disclosure.

FIGS. 1A and 1B illustrate various views of an example catheter system100 (or catheter assembly) that may be utilized with the teachings ofthe present disclosure, according to some embodiments. Specifically,FIG. 1A is an exploded view of the example catheter system 100 and FIG.1B is a cross-sectional side view of the example catheter system 100,after the example catheter system 100 has been assembled.

The catheter system 100 may generally include a needle assembly 110, aneedle-safety shield 140, a catheter adapter body 160, and a catheter170 coupled to and projecting from a distal end of the catheter adapterbody 160. The needle assembly 110 may include an introducer needle 120coupled to a needle hub 130. The needle-safety shield 140 may include aseptum 141 configured to slidably receive the introducer needle 120therethrough, and a contact surface 115 disposed at a distal end of theneedle-safety shield 140. The catheter adapter body 160 may include aproximal surface 165 configured to engage the contact surface 115 of theneedle-safety shield 140, as will be explained below in more detail withrespect to FIGS. 2A-8 .

FIGS. 2A-2C illustrate various views of a needle-safety shield 200 (orintermediate member), according to some embodiments. The needle-safetyshield 200 may be utilized in conjunction with the example cathetersystem 100 of FIGS. 1A and 1B, or with any other suitable cathetersystem known or contemplated in the art. The needle-safety shield 200may generally include a needle-safety shield portion 210 disposed at adistal end 202 of the needle-safety shield 200, and a ramp memberportion (or ramp member 220) disposed at a proximal end 201 of theneedle-safety shield 200.

The needle-safety shield portion 210 may include a contact surface 215at a distal end of the needle-safety shield portion 210. Theneedle-safety shield portion 210 may be configured to internally trap adistal end of the introducer needle 120 to protect a clinician againstaccidental exposure to the sharp distal end of the introducer needle120. The needle-safety shield portion 210 (and/or the ramp member 220)may further include one or more internal septa (not shown), which may beconfigured to facilitate the proper valving of fluids in a cathetersystem that utilizes the modified needle-safety shield 200 shown inFIGS. 2A-2C.

In at least some embodiments, the ramp member 220 may be integrallyformed with the needle-safety shield portion 210. For example, the rampmember 220 may be integrally formed with the needle-safety shieldportion 210 via an injection molding process. However, it will also beunderstood that in other embodiments, the ramp member 220 may not beintegrally formed with the needle-safety shield portion 210. Forexample, the ramp member 220 and the needle-safety shield portion 210may be separately formed and then coupled together via an adhesiveprocess, or not coupled together at all. Moreover, in some cathetersystem embodiments, the ramp member 220 may be utilized without theneedle-safety shield portion 210 to form a simple intermediate member.In yet further embodiments, the ramp member 220 may be combined with anynumber of different components in order to form any number of differentintermediate members that incorporate the ramp member 220.

In general, the ramp member 220 may include a first ramp surface 221, asecond ramp surface 222, a third ramp surface 223, a fourth ramp surface224, a first plateau portion 231, a second plateau portion 232, a firststop bump 241, a second stop bump 242, and a ramp projection 250 havingramp needle aperture 251 formed therethrough.

Each ramp surface may be angled relative to an introducer needle 120that may pass through the ramp needle aperture 251. A magnitude orsteepness of an angle associated with a given ramp surface willgenerally determine a magnitude of a distally directed force that may begenerated by a driving spring pressing against the ramp surface, as willbe discussed in more detail below.

In some embodiments, each ramp surface may also include a surfaceportion that includes a concave shape. For example, the first rampsurface 221 may include a first concave surface portion, the second rampsurface 222 may include a second concave surface portion, the third rampsurface 223 may include a third concave surface portion, and the fourthramp surface 224 may include a fourth concave surface portion. Moreover,each concave surface portion may have a radius that is associated witheach concave surface portion. For example, the first concave surfaceportion may have a first radius, the second concave surface portion mayhave a second radius, the third concave surface portion may have a thirdradius, and the fourth ramp surface may have a fourth radius. In atleast one embodiment, each of the first radius, the second radius, thethird radius, and the fourth radius may be substantially equal to eachother. However, it will also be understood that in other embodiments thefirst radius, the second radius, the third radius, and/or the fourthradius may be similar and/or different from each other in anycombination.

A magnitude of a radius associated with a concave ramp surface willgenerally determine a maximum force and a minimum force that may begenerated by a driving spring pressing against the concave ramp surface(which will be discussed in more detail below). The radius of theconcave ramp surface will also determine transitional forcecharacteristics that are imparted to an introducer needle as the drivingsprings moves along the concave ramp surface between the top of theconcave ramp surface (maximum force) toward the bottom of the concaveramp surface (minimum force). For example, a concave ramp surface may bedesigned with a radius that substantially normalizes early stage dragforces that are experienced by an introducer needle (e.g., when aclinician first begins withdrawing the introducer needle from a cathetersystem), by applying an appropriate maximum force to the introducerneedle early during withdrawal. However, as the clinician continues towithdraw the introducer needle from the catheter system, the drag forcesexperienced by the introducer needle will typically decrease.Accordingly, the radius of the concave ramp surface also helps theintroducer needle maintain a normalized drag force profile on theintroducer needle as it is withdrawn from the catheter system bycontinuously reducing the force applied to the introducer needle as thedriving spring moves along the concave ramp surface and transitionsbetween the maximum force (e.g., when the driving spring is at the topof the concave ramp surface) toward the minimum force (e.g., when thedriving spring is at the bottom of the concave ramp surface).

In some embodiments, the first stop bump 241 may be located adjacent toand/or intermediate the first and second ramp surfaces 221, 222 and thefirst plateau portion 231, and the second stop bump 242 may be locatedadjacent to and/or intermediate the third and fourth ramp surfaces 223,224 and the second plateau portion 232. The shape of the first andsecond plateau portions 231, 232 and the first and second stop bumps241, 242 may help to bias a driving spring to keep it in place on top ofthe ramp member 220 (e.g., fully loaded onto the ramp member 220) untila clinician is ready to withdraw the introducer needle from the cathetersystem.

The ramp projection 250 may also help reduce flexion and “wobble” in anintroducer needle passing through the ramp needle aperture 251. The rampprojection 250 may accomplish this by decreasing a length of theintroducer needle that is unsupported by other components of thecatheter system when the introducer needle is at least partiallywithdrawn from the catheter system.

FIGS. 3A-3C illustrate various views of a resilient member or drivingspring 300, according to some embodiments. Specifically, FIG. 3A is aperspective top view of the driving spring 300, FIG. 3B is a front viewof the driving spring 300, and FIG. 3C is a perspective top view of thedriving spring 300, shown pulled apart. In general, the driving spring300 includes a superior portion 301, an inferior portion 302, a firstresilient portion 341, and a second resilient portion 342.

The superior portion 301 may include a first spring arm 311, a secondspring arm 312, and a first cross-member 321 that couples the firstspring arm 311 to the second spring arm 312. Likewise, the inferiorportion 302 may include a third spring arm 313, a fourth spring arm 314,and a second cross-member 322 that couples the third spring arm 313 tothe fourth spring arm 314. The second resilient portion 342 may couplethe first spring arm 311 to the third spring arm 313 and the firstresilient portion 341 may couple the second spring arm 312 to the fourthspring arm 314. The first and second resilient portions 341, 342 mayeach apply one or more bias forces to the first and second cross-members321, 322 to urge the first and second cross-members 321, 322 toward eachother. In at least some embodiments, the first and second cross-members321, 322 may be configured to grasp an introducer needle between thefirst and second cross-members 321, 322 when the first and secondcross-members 321, 322 are urged together. For example, a spring needleaperture 325 may be formed between the first and second cross-members321, 322, as shown in FIG. 3B. The spring needle aperture 325 may besized to receive and/or grasp an introducer needle between the first andsecond cross-members 321, 322 when the first and second cross-members321, 322 are urged toward each other by the first and second resilientportions 341, 342.

In at least some embodiments, the first cross-member 321 may include afirst guide surface 331 and a second guide surface 332. The secondcross-member 322 may include a third guide surface 333 and a fourthguide surface 334. In these embodiments, the first ramp surface 221 maybe configured to receive the first guide surface 331 of the firstcross-member 321, the second ramp surface 222 may be configured toreceive the second guide surface 332 of the first cross-member 321, thethird ramp surface 223 may be configured to receive the third guidesurface 333 of the second cross-member 322, and the fourth ramp surface224 may be configured to receive the fourth guide surface 334 of thesecond cross-member 322. In this manner, the driving spring 300 may beconfigured to engage the ramp member 220 (once it has been loaded ontothe ramp member 220) and impart a force on the needle-safety shield 200to urge the needle-safety shield 200 in a distal direction relative tothe needle hub 130. This will then cause the contact surface 215 of theneedle-safety shield 200 to engage the proximal surface 165 of acatheter adapter body 160 and urge the catheter adapter body 160 in thedistal direction relative to the needle hub 130. This, in turn, willurge the catheter 170 in the distal direction relative to the introducerneedle 120. In this manner, the drag forces experienced by theintroducer needle 120 may be reduced and/or normalized in order toprovide a uniform operation/feel to the clinician that can help theclinician better guide the catheter 170 and advance or place thecatheter 170 within a blood vessel of a patient.

FIGS. 4A-4C illustrate various side views of the driving spring 300 asit is loaded onto the ramp member 220. FIG. 4A shows the driving spring300 before it is loaded onto the ramp member 220. FIG. 4A also shows howthe introducer needle 120 can be grasped between the first and secondcross-members 321, 322. In this manner, there is only a short length ofthe introducer needle 120 that is “unsupported” between the first andsecond cross-members 321, 322 and the tip of the ramp projection 250.This design results in reduced flexion and wobble that is experienced bythe introducer needle 120. FIG. 4B shows the driving spring 300 slidingup the ramp member 220 as it is loaded onto the ramp member 220, andFIG. 4C shows the driving spring 300 after it has been fully loaded ontothe ramp member 220. FIG. 4C also shows how the first and secondcross-members 321, 322 respectively fit within the first and secondplateau portions 231, 232 of the ramp member 220 to maintain the drivingspring 300 fully loaded onto the ramp member 220.

FIGS. 5A-6 illustrate various views of a resilient member or drivingspring 400 and an intermediate or ramp member 500, according toalternative embodiments of the present disclosure. Specifically, FIG. 5Ais a perspective top view of the driving spring 400 as it is loaded ontothe ramp member 500; FIG. 5B is a cross-sectional side view of thedriving spring 400 after it has been fully loaded onto the ramp member500; and FIG. 6 is a cross-sectional side view of an example catheterassembly or catheter system 600 incorporating the driving spring 400 andramp member 500 of FIGS. 5A and 5B.

The ramp member 500 may include a first ramp surface 521, a second rampsurface 522, a third ramp surface 523, a fourth ramp surface (notvisible in FIGS. 5A-6 ), a first plateau portion 531, a second plateauportion 532, a first stop bump 541, a second stop bump 542, and a rampprojection 550 having ramp needle aperture 551 formed therethrough. Thedriving spring 400 may include a first spring arm 411, a second springarm 412, and a first cross-member 421 that couples the first spring arm411 to the second spring arm 412. The driving spring 400 may alsoinclude a third spring arm 413, a fourth spring arm 414, and a secondcross-member 422 that couples the third spring arm 413 to the fourthspring arm 414. A second resilient portion 442 may couple the firstspring arm 411 to the third spring arm 413 and a first resilient portion441 may couple the second spring arm 412 to the fourth spring arm 414.The first and second resilient portions 441, 442 may each apply one ormore bias forces to the first and second cross-members 421, 422 to urgethe first and second cross-members 421, 422 toward each other. In atleast some embodiments, the first and second cross-members 421, 422 maybe configured to grasp an introducer needle between the first and secondcross-members 421, 422 when the first and second cross-members 421, 422are urged together. For example, a first spring plate 451 and a secondspring plate (not visible in FIGS. 5A-6 ) may be formed in the first andsecond cross-members 421, 422 and shaped to receive and/or grasp anintroducer needle between the first and second cross-members 421, 422when the first and second cross-members 421, 422 are urged toward eachother by the first and second resilient portions 441, 442.

As shown in FIG. 6 , the driving spring 400 may be coupled to the needlehub 130, and the ramp member 500 may be coupled to the needle-safetyshield 140. However, it will also be understood that the driving spring400 may be coupled to the needle-safety shield 140 and the ramp member500 may be coupled to the needle hub 130, in at least some embodiments.The driving spring 400 may be configured to engage the ramp member 500and impart a force on the needle-safety shield 140 to urge theneedle-safety shield 140 in a distal direction relative to the needlehub 130. This will then cause a contact surface of the needle-safetyshield 140 to engage a proximal surface of a catheter adapter body 160and urge the catheter adapter body 160 in the distal direction relativeto the needle hub 130. This, in turn, will urge the catheter 170 in thedistal direction relative to the introducer needle 120. In this manner,drag forces experienced by the introducer needle 120 from othercomponents of the catheter system 600 may be reduced and/or normalizedin order to provide a uniform operation and “feel” to the clinician,which can help the clinician better guide the catheter 170 and place thecatheter 170 within a blood vessel of a patient.

FIG. 7 illustrates a partial cross-sectional side view of an examplecatheter assembly or catheter system 700, according to an alternativeembodiment of the present disclosure. In general, the catheter system700 may include an introducer needle 710 comprising a needle bump 711, aneedle hub 720 coupled to the introducer needle 710, an intermediatemember 730 comprising a contact surface 715, a first resilient member741, a first bearing member 781 coupled to the first resilient member741, a second resilient member 742, a second bearing member 782 coupledto the second resilient member 742, a ramp member 750 comprising a firstramp surface 751 and a second ramp surface 752, a catheter adapter body760 comprising a proximal surface 765, and a catheter 770 extending froma distal end of the catheter adapter body 760.

The catheter system 700 may function in a similar manner to othercatheter systems described herein. However, in at least some embodimentsthe first and second bearing members 781, 782 may be configured torotate relative to the first and second resilient members, respectively.In this manner, friction between the first resilient member 741 and thefirst ramp surface 751 may be reduced, and friction between the secondresilient member 742 and the second ramp surface 752 may also bereduced. Moreover, the first and second resilient members 741, 742 maybe coupled to the intermediate member 730, and the ramp member 750 maybe coupled to the needle hub 720, as opposed to other catheter systemembodiments disclosed herein. In this manner, the first and secondresilient members 741, 742 may engage the first and second ramp surfaces751, 752 to impart a force on the intermediate member 730 and urge theintermediate member 730 in a distal direction relative to the needle hub720. This may cause the contact surface 715 of the intermediate member730 to engage the proximal surface 765 of the catheter adapter body 760and urge the catheter adapter body 760 in the distal direction relativeto the needle hub 720. This, in turn, may urge the catheter 770 in thedistal direction relative to the introducer needle 710. In this manner,drag forces experienced by the introducer needle 710 (from othercomponents in the catheter system 700) may be reduced and/or normalizedin order to provide a uniform drag force to the clinician to help theclinician guide the catheter 770 into a blood vessel of a patient.

FIG. 8 is a flow chart of a method 800 for inserting a catheter into ablood vessel of a patient, according to some embodiments of the presentdisclosure. The method 800 may be facilitated through use of a catheterassembly or catheter system comprising an introducer needle coupled to aneedle hub, an intermediate member having a contact surface disposed ata distal end of the intermediate member, a resilient member coupled toone of the needle hub and the intermediate member, and a ramp membercoupled to the other one of the needle hub and the intermediate member.

The method 800 may begin with a step 810 in which a distal end of theintroducer needle may be inserted into a blood vessel of a patient by aclinician.

Once the clinician has inserted the distal end of the introducer needleinto the blood vessel of the patient, the method 800 may proceed to astep 820 in which the clinician may advance the intermediate memberproximally relative to the introducer needle.

Once the clinician has advanced the intermediate member proximallyrelative to the introducer needle, the method 800 may proceed to a step830 in which the resilient member may be engaged with a ramp surface ofthe ramp member to impart a force on the intermediate member and urgethe intermediate member in a distal direction relative to the needlehub.

Once the resilient member has been engaged with the ramp surface and aforce has been imparted on the intermediate member to urge theintermediate member in the distal direction relative to the needle hub,the method 800 may proceed to a step 840 in which a contact surface ofthe intermediate member may be engaged with a proximal surface of acatheter adapter body to urge the catheter adapter body in the distaldirection relative to the needle hub.

Once the catheter adapter body has been urged in the distal directionrelative to the needle hub, the method 800 may proceed to a step 850 inwhich the catheter coupled to the catheter adapter body may be urged inthe distal direction relative to the introducer needle. In someembodiments, the catheter coupled to the catheter adapter body may beurged in the distal direction relative to the introducer needle in orderto insert a distal end of the catheter into the blood vessel or furtheradvance the introducer needle within the blood vessel.

Alternatively, or in addition thereto, the method 800 may also proceedto any one or more of steps 860, 870, and/or 880. For example, once thecatheter has been urged in the distal direction relative to theintroducer needle, the method 800 may proceed to the step 860 and/or thestep 870 in which the needle hub and the introducer needle may be movedin a proximal direction relative to the catheter and the introducerneedle may be fully, or at least partially, withdrawn from the catheter.Once the introducer needle has been at least partially withdrawn fromthe catheter, the method 800 may further proceed to the step 880 inwhich the introducer needle may be grasped between first and secondcross-members of the resilient member as the introducer needle is atleast partially withdrawn from the catheter, and the method 800 may end.

Any methods disclosed herein include one or more steps or actions forperforming the described method. One or more of the method steps and/oractions may be omitted from any of the methods disclosed herein.Moreover, any of the method steps and/or actions may be interchangedwith one another. In other words, unless a specific order of steps oractions is required for proper operation of the embodiment, the orderand/or use of specific steps and/or actions may be modified.

It will be understood that any number of different driving springconfigurations and/or styles may be utilized with the general conceptsdisclosed in the present invention to reduce early stage drag forcesthat are imparted on an introducer needle within a given cathetersystem. For example, other driving spring configurations contemplatedherein may include a helical spring configuration (not shown) that maybe utilized to impart a force on an intermediate member to reduce earlystage drag forces that are imparted on an introducer needle within agiven catheter system.

Moreover, any number of ramp surfaces, configurations, and/or shapes arecontemplated herein to achieve a desired force profile that willoptimally reduce and/or normalize drag forces imparted on an introducerneedle for a given catheter system, without departing from the spirit orscope of the present application. Thus, the number of ramp surfaces,plateaus, and stop bumps, as well as their configurations and/or shapes,can be varied in order to fine-tune any number of parameters including,but not limited to: (1) release timing for the driving spring; (2) thesmoothness of the driving spring before/during release of the drivingspring and/or during actuation of the driving spring along its fullrange of motion; (3) adjusting the maximum and/or minimum forcesprovided by the driving spring; (4) adjusting any transitionalcharacteristics of the driving spring force as the driving springtransitions between a given maximum and minimum force; (5) adjusting anaverage force provided by the driving spring (e.g., either throughadjusting an angle of a ramp and/or by adjusting a strength of thedriving spring itself), etc.

It will also be noted that in at least some embodiments, a maximumdriving force may be chosen that will not exceed the drag forces appliedto the introducer needle by a given catheter system. In this manner,unintentional self-advancement of the catheter may be avoided, and/oradvancement of the catheter at a more rapid rate than is expected by theclinician may also be avoided.

Reference throughout this specification to “an embodiment” or “theembodiment” means that a particular feature, structure or characteristicdescribed in connection with that embodiment is included in at least oneembodiment. Thus, the quoted phrases, or variations thereof, as recitedthroughout this specification are not necessarily all referring to thesame embodiment. It is to be understood that any of the embodiments ofthe present disclosure, or any portion(s) of any of the embodiments ofthe present disclosure, may be combined together in any number ofdifferent ways.

Similarly, it should be appreciated that in the above description ofembodiments, various features are sometimes grouped together in a singleembodiment, Figure, or description thereof for the purpose ofstreamlining the disclosure. This disclosure format, however, is not tobe interpreted as reflecting an intention that any claim requires morefeatures than those expressly recited in that claim. Rather, as thefollowing claims reflect, inventive aspects lie in a combination offewer than all features of any single foregoing disclosed embodiment.Thus, the claims following this Description Of Embodiments are herebyexpressly incorporated into this Description Of Embodiments, with eachclaim standing on its own as a separate embodiment. This disclosureincludes all permutations of the independent claims with their dependentclaims.

Recitation in the claims of the term “first” with respect to a featureor element does not necessarily imply the existence of a second oradditional such feature or element. Elements recited inmeans-plus-function format are intended to be construed in accordancewith 35 U.S.C. § 112 Para. 6. It will be apparent to those having skillin the art that changes may be made to the details of theabove-described embodiments without departing from the underlyingprinciples set forth herein.

Standard medical directions, planes of reference, and descriptiveterminology are employed in this specification. For example, anteriormeans toward the front of the body. Posterior means toward the back ofthe body. Superior means toward the head. Inferior means toward thefeet. Medial means toward the midline of the body. Lateral means awayfrom the midline of the body. Axial means toward a central axis of thebody. Abaxial means away from a central axis of the body. Ipsilateralmeans on the same side of the body. Contralateral means on the oppositeside of the body. A sagittal plane divides a body into right and leftportions. A midsagittal plane divides the body into bilaterallysymmetric right and left halves. A coronal plane divides a body intoanterior and posterior portions. A transverse plane divides a body intosuperior and inferior portions. These descriptive terms may be appliedto an animate or inanimate body.

The phrases “connected to,” “coupled to,” “engaged with,” and “incommunication with” refer to any form of interaction between two or moreentities, including mechanical, electrical, magnetic, electromagnetic,fluid, and thermal interaction. Two components may be functionallycoupled to each other even though they are not in direct contact witheach other. The term “abutting” refers to items that are in directphysical contact with each other, although the items may not necessarilybe attached together. The phrase “fluid communication” refers to twofeatures that are connected such that a fluid within one feature is ableto pass into the other feature.

As defined herein, “substantially equal to” means “equal to,” or withinabout a + or − 10% relative variance from one another.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. While the various aspects of theembodiments are presented in the Figures, the Figures are notnecessarily drawn to scale unless specifically indicated.

While specific embodiments and applications of the present disclosurehave been illustrated and described, it is to be understood that thescope of the appended claims is not limited to the precise configurationand components disclosed herein. Various modifications, changes, andvariations which will be apparent to those skilled in the art may bemade in the arrangement, operation, and details of the apparatus andsystems disclosed herein.

All examples and conditional language recited herein are intended forpedagogical objects to aid the reader in understanding the invention andthe concepts contributed by the inventor to furthering the art, and areto be construed as being without limitation to such specifically recitedexamples and conditions. Although embodiments of the present disclosurehave been described in detail, it should be understood that the variouschanges, substitutions, and alterations could be made hereto withoutdeparting from the spirit and scope of the present disclosure.

The invention claimed is:
 1. A catheter assembly, comprising: anintroducer needle coupled to a needle hub; an intermediate membercomprising a contact surface disposed at a distal end of theintermediate member, the intermediate member configured to slidablyreceive the introducer needle therethrough; a catheter adapter body; acatheter projecting from a distal end of the catheter adapter body; aramp member coupled to the needle hub, wherein the ramp member comprisesa first ramp surface and a second ramp surface opposite the first rampsurface; a first resilient member and a second resilient member; a firstbearing member configured to rotate with respect to the first resilientmember; and a second bearing member configured to rotate with respect tothe second resilient member, wherein the first bearing member isconfigured to engage the first ramp surface and the second bearingmember is configured to engage the second ramp surface, wherein thefirst bearing member and the second bearing member impart a force on thefirst ramped surface and the second ramped surface, respectively, tourge the intermediate member in a distal direction relative to theneedle hub, wherein the contact surface of the intermediate member isconfigured to engage a proximal surface of the catheter adapter body andurge the catheter adapter body in the distal direction relative to theneedle hub.
 2. The catheter assembly of claim 1, further comprising adriving spring, wherein the driving spring comprises the first resilientmember and the second resilient member.
 3. The catheter assembly ofclaim 1, wherein the first ramp surface comprises a concave surfaceportion, wherein the second ramp surface comprises another concavesurface portion, wherein the first bearing member is disposed within theconcave surface portion and the second bearing member is disposed withinthe another concave surface portion.
 4. The catheter assembly of claim1, wherein the first ramp surface comprises a plateau portion, whereinthe second ramp surface comprises another plateau portion.
 5. A methodof inserting a catheter into a blood vessel of a patient through use ofa catheter assembly comprising: an introducer needle coupled to a needlehub; an intermediate member comprising a contact surface disposed at adistal end of the intermediate member, the intermediate memberconfigured to slidably receive the introducer needle therethrough; acatheter adapter body; a catheter projecting from a distal end of thecatheter adapter body; a ramp member coupled to the needle hub, whereinthe ramp member comprises a first ramp surface and a second ramp surfaceopposite the first ramp surface; a first resilient member and a secondresilient member; a first bearing member configured to rotate withrespect to the first resilient member; and a second bearing memberconfigured to rotate with respect to the second resilient member,wherein the first bearing member is configured to engage the first rampsurface and the second bearing member is configured to engage the secondramp surface, wherein the first bearing member and the second bearingmember impart a force on the first ramped surface and the second rampedsurface, respectively, to urge the intermediate member in a distaldirection relative to the needle hub, wherein the contact surface of theintermediate member is configured to engage a proximal surface of thecatheter adapter body and urge the catheter adapter body in the distaldirection relative to the needle hub; the method comprising: inserting adistal end of the introducer needle within the blood vessel of thepatient; and advancing the intermediate member proximally relative tothe introducer needle, thereby: engaging the first resilient member andthe second resilient member with the first ramp surface and the secondramp surface, respectively, to impart the force on the intermediatemember and urge the intermediate member in the distal direction relativeto the needle hub; engaging the contact surface of the intermediatemember with the proximal surface of the catheter adapter body to urgethe catheter adapter body in the distal direction relative to the needlehub; and urging the catheter coupled to the catheter adapter body in thedistal direction relative to the introducer needle.
 6. The method ofclaim 5, further comprising: moving the needle hub and the introducerneedle in a proximal direction relative to the catheter; and withdrawingthe introducer needle from the catheter.
 7. The method of claim 5,further comprising a driving spring, wherein the driving springcomprises the first resilient member and the second resilient member. 8.The method of claim 5, wherein the first ramp surface comprises aconcave surface portion, wherein the second ramp surface comprisesanother concave surface portion, wherein the first bearing member isdisposed within the concave surface portion and the second bearingmember is disposed within the another concave surface portion.
 9. Themethod of claim 5, wherein the first ramp surface comprises a plateauportion, wherein the second ramp surface comprises another plateauportion.